The NRL center for Cryslallographic Studies will provide definitive, three dimensional structural parameters. The compounds to be consist of two groups: 1) ncn-peptide substances and are either drugs of abuse, their analogs, related probes, or potential therapeutics. NRL will investigate 40-50 oompounds per year. 2) opioid and related peptites (CCK-relatad. FMRF?ralated alphs-MSH related, fragments. ele.) NRL will investigate 20-35 peptides per year.